Control mechanism for presses



Sept. 5, '1939. E. L. HYDE 2,171,564

CONTROL MECHANISM FOR PRESSES Filed Sept. :5, 1957 FlG.-l 24 22 23 INVENTOR ELBERT L. HYDE Y Patented Sept. 5, 1939 UNITED STATES PATENT OFFICE Ohio Application September 3, 1937, Serial No. 162,293

4 Claims.

This invention relates to improvements in pressing machine control mechanism.

An object of the invention is to provide a novel control mechanism for a power closed pressing machine in which the control means for the power means is operated by two spaced safety manuals. These manuals have two stages of operation, a first stage for energizing the power means but during which, upon release of one or both manuals, the press opens; and a second stage of operation for setting a stay-put valve for holding the power means energized, after which the manuals may be released and the press will remain closed. The second stage of manual operation is prevented until the press is safely closed.

The novel features of my invention will be more clearly understood from the accompanying drawing and description and the essential features will be summarized in the claims.

In the drawing, Fig. 1 shows an end elevation of a pressing machine in open position with my novel control mechanism shown diagrammatical- 1y; Fig. 2 is a similar view showing the pressing machine in safe closed position and showing the control mechanism in a corresponding position;

Fig. 3 is a diagrammatic view of the control mechanism of Figs. 1 and 2, showing the position of the parts after second stage operation of the manuals; while Fig. 4 is a diagrammatic View of the control mechanism after the press is fully elosed'and the manuals are released.

In Fig. 1 I have shown a pressing machine having a frame III carrying a bed II and a yoke I2 adapted by oscillation to move a pressing head I3 into and out of engagement withthe bed II in response to movement of toggles I4 bya fluid motor I5. A valve I6 is provided with a casing I1 and a core I8. The casing H has ports I'Ia, Ill) and H0. The core I8 has a Y-shaped passage I8a. The core has a rigid operating arm I8b which is connected by a yieldable link I9 with a whifiletree 20. The opposite ends of the Whifiletree are connected by links 2I with manuals 22 and 23 respectively. These manuals are normally held in unactuated position by springs 24. Blocks 25 limit the manuals to a first stage of movement until the press is safely closed. These blocks are rigid with shaft 26 which has an arm 21 connected by rod 28 to a portion of the press mechanism. In the present instance this rod passes through a slotted bracket 29 on toggle I4. The rod has collars 28a and 28b and is normally biased to hold the blocks in the position of Fig. 1 by a spring 30.

Valve 3i has a casing 32 and a core 33. The

casing has ports 32a, 32b, 32c and 32d. The core has a passageway 33a and is provided with a rigid arm 33b which has a slotted connection with one arm of bellcrank 34 which is pivotally mounted at 34a on a suitable part of the frame. A pin 2611 on the Whifiletree is adapted to engage the other arm of bellcrank 34 during the press operation. Motive fluid is supplied at conduit 35 which leads to port 320 and through conduit 36 is in communication with port I'Ib. Conduits 31 and 38 connect motor I5 with ports I'Ia. Conduits 31 and 39 connect motor I5 with port 32d. Conduit II] connects ports I10 and 32a.

In operation, with the pressing machine in the open position of Fig. 1, the operator depresses manuals 22 and 23 until they engage blocks 25. Operation of both manuals is necessary to move core I8 from the position of Fig. 1 to that ofFig. 2, During this movement the yieldable link I9 is not compressed. When valve I6 is thus moved to the position of Fig. 2, fluid is supplied to motor I5 through conduits 35 and 36, core passage I81; and conduits 38 and 31. This will close the press, but upon release of either manual springs 24 will return the manuals, moving the whifiletree 2|] so that core I8 is moved partially or entirely back to the position of Fig. 1 and sufficiently to disestablish the supply through valve I6, whereupon the press of course would open. When the press reaches safe closed position, blocks 25 are moved to the position of Fig. 3 by the straightening toggles acting through rod 28. This permits second stage movement of the manuals to the position of Fig. 3, during which time the core I8 of valve I6 remains in the same position as in Fig. 2 because of stop II, which causes a compression of the yieldable link I9. This additional movement of the manuals, however, causes sufficient movementofwhiffletr'ee to cause the arm 20a'thereof to engage bellcrank 34, moving it in a clockwise direction about its pivot and moving the core 33 of valve 3| to the position of Fig. 3. It will be noted that in the position of Figs. 1 and 2 the passageway 33a of this core 33 serves as a portion of the exhaust passage from motor I5. However, when moved to the position of Fig. 3, the core 33 cuts off the exhaust conduit 46 and establishes a by-pass supply for motor I5 independently of valve I6. This by-pass supply is through conduit 35, port 320, core passage 33a, port 32d and conduits 39 and 31. Since valve 3| is of the stay-put type and will remain in any position in which it is placed, the manuals may now be released as shown in Fig. 4, whereupon these manuals in valve I6 return to the now closed because of the changed position of the valve core 33. The press thus remains closed until the operator moves arm 34b of the bellcrank 34 in a clockwise direction, returning valve 3| to the position of Fig. 1, thus exhausting motor l5 and permitting the press to open.

What I claim is: 1. In a pressing machine having coacting relatively movable pressing members and power actuated operating mechanism therefor, a primary power supply control member for, said mechai nism, spaced safety manual means for actuating said control member, saidmanual means having two stages of operation, a first stage for actuating said pressing members to closed position and a second stage comprising a movement other than'said first stage movement for causing a maintaining of said members in closed position, there'being an operative connection between said control member and said manual means in the first stage of operation arranged to require coincidental use of both hands of an operator to eifectively actuate said control member to power supply position, said control member being nor mally urged to power cut-off position when said manual means is released, means preventing sec 0nd stage movement of said manual means until saidpressing members reach safe-closed'position, a secondary power supply control member for said mechanism independent of said primary control member, said secondary control member beingarranged for movement to power supply position by second stage movement of said man-' ual means, and said secondary control member being movable to fluid cut-off position to cause opening of the press. l 2. In a pressing machine havingcoacting relatively movable pressing members and power actuated operating mechanism therefor, a primary power supply control member for said mechanism, spaced safety manual means for actuating said control member, said manual means having two stages of operation, a first-stage for actuatingsaid I pressing members to closed position and a second stage comprising a movement other than said first stage movement for causing a maintaining of said members in closed position, there being an'operative connection between'said con-l trol member and said manual means in the first stage of operation arranged to require coincidental use of. both' hands of an operator to effectively actuate said control member to power supply position, said control member being normally urged to power cut-off positionwhen said manual means is released, means preventing sec 0nd stage movement of said manual means until said pressing members reach safe-closed position, a secondary power supply control member for said mechanism independent of said primary control member, said secondary control member being adapted to stay put in a position in which it is placed, said secondary control member being arranged for movement to power supply position by second stage movement of said man- 'ual means, and said secondary control member being movable to fluid cut-off position to cause opening of the press.

'3. Ina pressing machine having coacting relatively movable pressing members and fluid actuated operating mechanism therefor, primary 7 and secondary fluid supplies for said mechanism,

eachincluding a valve in series in the supply system having a normally'closed fluid inlet passages thereof, said second stage comprising a movement other than said first stage movement, means preventing second stage operation of said manual means until said pressing members reach safe-closed position, and said secondary supply .valve being movable to fluid cut-off position to cause opening of. the press.

4. In a pressing machine having coacting rela-' tively movable pressing members and fluid actuated operating mechanism therefor, primary and secondary fluid supplies for said mechanism, control'means for said primary fluid supply normally urged to fluid cut-off position, control means for said secondary fluid supply, two-hand safety manual means for actuating said control means, said manual means having two stages of operation, first and second stages respectively for actuating said primary and secondary supply control means to fluid supply position, said second-stage comprising a movement other than said first stage movement, means preventing sec- 0nd stage movement of said manual means until said pressing members reach safe-closed position, and said secondary supply control means being movable to fluid cut-off position to cause opening of the press. 7 p

, ELBERT L. HYDE. 

